Vibration motor

ABSTRACT

In a vibration motor, a substrate is disposed on a base plate, a coil is disposed on the substrate, and a magnet is disposed so as to be accommodated in an inner peripheral side of the coil having an annular shape by vibration. A back yoke is disposed on the magnet, a weight is disposed on the back yoke, and a case accommodates the coil, the magnet, the back yoke, and the weight. An elastic member is disposed between the case and the weight. The base plate, the case, the magnet, the back yoke, and the weight are each formed to have a rectangular shape including long sides that extend in a first direction orthogonal to a vertical direction and short sides that extend in a second direction orthogonal to the vertical direction and the first direction in a top view.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. PatentApplication No. 62/394,300 filed on Sep. 14, 2016 and Japanese PatentApplication No. 2016-193225 filed on Sep. 30, 2016. The entire contentsof these applications are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a vibration motor.

2. Description of the Related Art

In the related art, various devices such as a smartphone and the likeare provided with a vibration motor. Among vibration motors, there are atype of vibration motor that performs linear vibration in a horizontaldirection and a type of vibration motor that performs linear vibrationin a longitudinal direction. A human being who is a user is more likelyto sense vibration in the longitudinal direction than vibration in thehorizontal direction. An example of a longitudinal linear vibration typeof vibration motor in the related art is described in JapaneseUnexamined Patent Application Publication No. 2013-85438.

The vibration motor described in Japanese Unexamined Patent ApplicationPublication No. 2013-85438 includes a fixed portion, a magnetic fieldportion, a substrate, a vibration portion, and an elastic member. Thefixed portion has a case with a lower portion that is open and a bracketfor sealing an internal space of the case. The magnetic field portionhas a magnet fixed on the bracket and a yoke plate fixed on the magnet.The vibration portion has a coil and a mass body. The substrate is fixedto the lower surface of the coil. The elastic member is disposed betweenthe case and the vibration portion. The coil has an inner diameter thatis larger than an outer diameter of the opposing magnet, and a portionof the magnet can be inserted into the space formed by the coil.

When the coil is energized via the substrate, the vibration portionvibrates in the longitudinal direction due to the interaction betweenthe magnetic field generated in the coil and the magnetic field formedby the magnet.

In smartphones, wearable devices, and the like in which vibration motorsare mounted, a larger battery tends to be mounted in order to realizelong time driving and thus the degree of freedom with respect to thedisposition location and disposition volume of the vibration motor issmall.

Particularly, since a dead space in the device described above is arectangular space such as at the side of a battery, it is required todispose a vibration motor in this space.

However, in the vibration motor described in Japanese Unexamined PatentApplication Publication No. 2013-85438, an outer appearance shaperesulting from the case and the bracket is a columnar shape, and thusthe vibration motor cannot be disposed in a rectangular space asdescribed above.

SUMMARY OF THE INVENTION

In an exemplary embodiment of the invention, there is provided avibration motor including: a stationary portion which has a base plate,a substrate, a coil, and a case; a vibrating body which has a magnet, aback yoke, and a weight and is supported by the stationary portion so asto be capable of vibrating in a vertical direction; and an elasticmember.

The substrate is disposed on the base plate, the coil is disposed on thesubstrate, and the magnet is disposed so as to be accommodated on aninner peripheral side of the coil having an annular shape by vibration.

The back yoke is disposed on the magnet, the weight is disposed on theback yoke, and the case accommodates the coil, the magnet, the backyoke, and the weight.

The elastic member is disposed between the case and the weight.

The base plate, the case, the magnet, the back yoke, and the weight eachhave a rectangular shape including long sides that extend in a firstdirection orthogonal to the vertical direction and short sides thatextend in a second direction orthogonal to the vertical direction andthe first direction in a top view.

According to an exemplary embodiment of the present application, it ispossible to provide a vibration motor of a longitudinal linear vibrationtype which can be disposed in a rectangular dead space in a device.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall perspective view of a vibration motor according toan embodiment of the invention as viewed from above.

FIG. 2 is an overall perspective view of the vibration motor accordingto the embodiment of the invention as viewed from below.

FIG. 3 is a perspective view illustrating a state where a case isremoved from the vibration motor illustrated in FIG. 1.

FIG. 4 is a side sectional view of the vibration motor according to theembodiment of the invention.

FIG. 5 is a top view illustrating a state where the case is removed fromthe vibration motor according to the embodiment of the invention.

FIG. 6 is a perspective view illustrating a configuration including amodification example of an elastic member.

FIG. 7 is a schematic view for illustrating an appropriate position of adamper member.

FIG. 8 is an overall perspective view of a back yoke.

FIG. 9 is a partially enlarged perspective view illustrating a state inwhich the case is removed from the vibration motor according to theembodiment of the invention.

FIG. 10 is a perspective view illustrating a configuration in which asubstrate and a coil are disposed on a base plate.

FIG. 11 is a perspective view illustrating a configuration in which asubstrate is disposed on a base plate.

FIG. 12 is a perspective view for illustrating fixation of the coil by ajig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an exemplary embodiment of the invention will be describedwith reference to the drawings. In the following drawings, a vibrationdirection of the vibrating body is a vertical direction and is expressedas an X-direction. In addition, a first direction which is a directionorthogonal to the vertical direction is expressed as a Y-direction. Inaddition, a second direction which is a direction orthogonal to thevertical direction and the first direction is expressed as aZ-direction. However, the definitions of these directions do notrepresent the positional relationships and directions when the vibratingbody is incorporated into an actual device.

<1. Overall Configuration of Vibration Motor>

First, the overall configuration of a vibration motor according to oneembodiment of the invention will be described with reference to FIGS. 1to 4. FIG. 1 is an overall perspective view of a vibration motor 15according to an embodiment of the invention as viewed from above. FIG. 2is an overall perspective view of the vibration motor 15 as viewed frombelow. FIG. 3 is a perspective view illustrating a state where a case 4has been removed from the vibration motor 15 illustrated in FIG. 1. FIG.4 is a side sectional view of the vibration motor 15.

The vibration motor 15 according to the present embodiment roughlyincludes a stationary portion 5, a vibrating body 10, and an elasticmember 11.

The stationary portion 5 has a base plate 1, a substrate 2, a coil 3,and a case 4. The base plate 1 is, for example, a metal plate-likemember. The base plate 1 is formed in a rectangular shape having longsides that extend in the first direction and short sides that extend inthe second direction in a top view.

The substrate 2 is disposed on the base plate 1 and is formed of aflexible printed circuit board (FPC). The substrate 2 may be formed of arigid substrate. The substrate 2 has a first substrate portion 21, asecond substrate portion 22, and a connection portion 23. The firstsubstrate portion 21, the connection portion 23, and the secondsubstrate portion 22 are arranged in this order in the first direction.The width of the first substrate portion 21 in the first direction issmaller than the width of the second substrate portion 22 in the firstdirection. The widths of the first substrate portion 21 and the secondsubstrate portion 22 in the second direction are identical to each otherand are larger than the width of the connection portion 23 in the seconddirection.

Two first terminal portions 21A are formed on the first substrateportion 21 side by side in the second direction and are exposed at anupper surface side thereof. Two second terminal portions 23A are formedon the connection portion 23 side by side in the second direction andare exposed at the upper surface side thereof. The first terminalportions 21A and the second terminal portions 23A that are adjacent toeach other in the first direction are connected to each other by wiringof the substrate 2 and are electrically connected to each other.

The coil 3 is disposed on the second substrate portion 22 of thesubstrate 2. In a top view, the coil 3 is formed in an annular shapehaving long sides that extend in the first direction and short sidesthat extend in the second direction. A lead wire that extends from thecoil 3 is connected to the second terminal portion 23A. Accordingly, acurrent can flow through the coil 3 by applying a voltage to the firstterminal portion 21A from the outside.

The case 4 is a rectangular-parallelepiped-shaped cover member having arectangular shape with long sides that extend in the first direction andshort sides that extend in the second direction in a top view, and whoselower surface is open. The coil 3, the vibrating body 10, and theelastic member 11 are accommodated in the internal space of the case 4.

The vibrating body 10 has a magnet 6, a back yoke 7, a weight 8, and apole piece 9. The magnet 6 is a rectangular parallelepiped member havinga rectangular shape having long sides that extend in the first directionand short sides that extend in the second direction in a top view.

The back yoke 7 is disposed on the magnet 6 and is formed of a magneticbody. The back yoke 7 has a top surface portion 71, two long sideprotrusion portions 72, and two short side protrusion portions 73. Thetop surface portion 71 has a rectangular shape having long sides thatextend in the first direction and short sides that extend in the seconddirection in a top view. The long side protrusion portions 72 protrudedownward from long side portions of the top surface portion 71 that faceeach other in the second direction. The short side protrusion portions73 protrude downward from short side portions of the top surface portion71 that face each other in the first direction.

The weight 8 is disposed on the back yoke 7 and is formed of, forexample, a tungsten alloy. In a top view, the weight 8 is a rectangularparallelepiped member having a rectangular shape having long sides thatextend in the first direction and short sides that extend in the seconddirection.

The pole piece 9 is disposed on the lower surface of the magnet 6 and isa plate-like member formed of a magnetic body. The pole piece 9 has arectangular shape having long sides that extend in the first directionand short sides that extend in the second direction in a top view. Amagnetic path is formed by the magnet 6, the back yoke 7, and the polepiece 9.

One end side of the elastic member 11 is fixed to a lower surface of thetop surface portion 41 of the case 4 and the other end side thereof isfixed to an upper surface 81 of the weight 8. In other words, theelastic member 11 is disposed between the case and the weight 8.Accordingly, the vibrating body 10 is supported so as to be capable ofvibrating in the vertical direction with respect to the stationaryportion 5.

The magnet 6 and the pole piece 9 are accommodated in an innerperipheral space of the coil 3 depending on the position at the time ofvibration. In other words, the magnet 6 is disposed so as to be capableof being accommodated on the inner peripheral side of the annular coil 3by the vibration.

The vibrating body 10 vibrates in the vertical direction due to acurrent flowing through the coil 3 when a voltage is applied from theoutside to the first terminal portion 21A of the substrate 2 and aninteraction between the magnetic field generated in the coil 3 and themagnetic field formed by the magnet 6, the back yoke 7, and the polepiece 9. Therefore, the vibration motor 15 is of the longitudinal linearvibration type.

As described above, the base plate 1, the case 4, the magnet 6, the backyoke 7, and the weight 8 each have a rectangular shape having long sidesthat extend in the first direction and short sides that extend in thesecond direction in a top view. Accordingly, it is possible to disposethe longitudinal linear-vibration-type vibration motor 15 in arectangular dead space such as at the side of a battery in a device suchas a smartphone or a wearable device.

<2. Configuration of Elastic Member>

Next, a more specific configuration of the elastic member 11 will bedescribed with reference to FIG. 5. FIG. 5 is a top view illustrating astate where the case 4 is removed from the vibration motor 15.

As illustrated in FIG. 5, the elastic member 11 includes a firstextension portion 11A, a second extension portion 11B, a firstconnection portion 11C, a second connection portion 11D, a thirdextension portion 11E, a fourth extension portion 11F, a thirdconnection portion 11G, a fourth connection portion 11H, and a fifthconnection portion 11I, and these portions are formed as one piece.

The first extension portion 11A and the second extension portion 11Bextend in the first direction and are adjacent to each other in thesecond direction in a top view. The first connection portion 11Cconnects one end portion of the first extension portion 11A and one endportion of the second extension portion 11B to each other. The secondconnection portion 11D connects the other end portion of the firstextension portion 11A and the other end portion of the second extensionportion 11B to each other.

The third extension portion 11E extends in the first direction and facesthe first extension portion 11A in the second direction. The fourthextension portion 11F extends in the first direction and is adjacent tothe third extension portion 11E in the second direction in a top view.The third connection portion 11G connects one end portion of the thirdextension portion 11E and one end portion of the fourth extensionportion 11F to each other. The fourth connection portion 11H connectsthe other end portion of the third extension portion 11E and the otherend portion of the fourth extension portion 11F to each other.

The fifth connection portion 11I connects the center portion of thefirst extension portion 11A and the center portion of the thirdextension portion 11E to each other in the second direction.

With such a configuration, only one elastic member 11 is needed and thusthe number of parts can be reduced.

Further, when the configuration of the elastic member 11 is describedwith reference to FIG. 3, the first extension portion 11A is inclinedupward from the center portion toward both the end portions thereof. Thesecond extension portion 11B is inclined upward from both the endportions toward the center portion thereof. The second extension portion11B has a welded portion 11J at the uppermost place of the inclination.In addition, the third extension portion 11E is inclined upward from thecenter portion toward both the end portions thereof. The fourthextension portion 11F is inclined upward from both the end portionstoward the center portion thereof. The fourth extension portion 11F hasa welded portion 11K at the uppermost place of the inclination.

With such a configuration, the vibrating body 10 can be supported to thecase 4 so as to be capable of vibrating by the fifth connection portion11I being fixed to the upper surface 81 of the weight 8 by welding andthe welded portions 11J and 11K positioned above the fifth connectionportion 11I being fixed to the lower surface of the top surface portion41 of the case 4 by welding.

As a modification example of the elastic member, an elastic member 11′configured as illustrated in FIG. 6 may be used. In the elastic member11′, the first extension portion 11′A is inclined downward from thecenter portion toward both end portions thereof. The second extensionportion 11′B is inclined downward from both end portions toward thecenter portion thereof. The second extension portion 11′B has a weldedportion 11′J at the lowermost place of the inclination. In addition, thethird extension portion 11′E is inclined downward from the centerportion toward both end portions thereof. The fourth extension portion11′F is inclined downward from both end portions toward the centerportion thereof. The fourth extension portion 11′F has a welded portion11′K at the lowermost place of the inclination.

With such a configuration, the vibrating body 10 can be supported to thecase 4 so as to be capable of vibrating by the welded portions 11′J and11′K being fixed to the upper surface 81 of the weight 8 by welding andthe fifth connection portion 11′1 positioned above the welded portions11′J and 11′K being fixed to the lower surface of the top surfaceportion 41 of the case 4 by welding.

In addition, in the elastic member 11 (FIG. 5), the widths of the firstconnection portion 11C, the second connection portion 11D, the thirdconnection portion 11G, and the fourth connection portion 11H are widerthan the widths of the first extension portion 11A, the second extensionportion 11B, the third extension portion 11E, and the fourth extensionportion 11F. Accordingly, it is possible to disperse the stress appliedto the elastic member 11 when the vibrating body 10 vibrates. This alsoapplies to the elastic member 11′ as a modification example.

<3. Disposition Configuration of Damper Member>

As illustrated in FIG. 3 and FIG. 5, the vibration motor 15 according tothe present embodiment further includes damper members 12A to 12D on theupper surface 81 of the weight 8. In a top view, the damper members 12Aand 12B, that is, at least one damper member is disposed in a regionsurrounded by the first extension portion 11A, the second extensionportion 11B, the first connection portion 11C, and the second connectionportion 11D. The damper members 12A and 12B are disposed at positionsseparated from each other in the first direction from the center portionof the region described above, respectively.

In addition, in a top view, the damper members 12C and 12D, that is, theat least one damper member is disposed in a region surrounded by thethird extension portion 11E, the fourth extension portion 11F, the thirdconnection portion 11G, and the fourth connection portion 11H. Thedamper members 12C and 12D are disposed at positions separated from eachother in the first direction from the center portion of the regiondescribed above, respectively.

By providing such damper members 12A to 12D, when the vibration motor 15is accidentally dropped or the like, it is possible to suppress thenoise generated by the weight 8 excessively moving upward and theelastic member 11 (fifth connection portion 11I and the like) cominginto contact with the lower surface of the top surface portion 41 of thecase 4.

In addition, since the damper members 12A to 12D can be disposed insidethe region where the elastic member 11 is disposed, the dispositionspace thereof can be omitted.

As illustrated in FIG. 5, for example, the damper members can bedisposed at a place P1 interposed between the damper members 12A and 12Cin the second direction and a place P2 interposed between the dampermembers 12B and 12D in the second direction. In other words, at leastone damper member may be disposed in a region interposed between thefirst extension portion 11A and the third extension portion 11E. In thiscase, it may be disposed together with the damper members 12A to 12D ormay be disposed only at the places P1 and P2. Even with such aconfiguration, it is possible to achieve the same effect as the effectdescribed above.

In other words, the configuration relating to the damper membersdescribed above can be said as a configuration that at least one dampermember is disposed in an area occupied by the elastic member 11 in a topview. Accordingly, it is possible to save the disposition space for thedamper members.

Next, an appropriate position of the damper member will be describedwith reference to FIG. 7. FIG. 7 is a schematic view illustrating theweight 8, the elastic member 11, and the damper member 12 as viewed froma side and illustrates a state where each of these configurations (thatis, the vibrating body 10) is inclined clockwise by an angle θ from thefirst direction.

When a height in the vertical direction from a line L1 extending andpenetrating an intersection point S in the first direction where theside interposed between the upper side and the lower side of the dampermember 12 intersects the upper side of the elastic member to one endportion of the upper side of the elastic member 11 is referred to as W,W is expressed by the following equation (1).W=X sin θ  (1)

Where, X: the distance from one end portion of the upper side of theelastic member 11 to the intersection point S.

In addition, when the height in the vertical direction from the line L1to one end portion of the upper side of the damper member 12 is referredto as Z, Z is expressed by the following equation (2).Z=(A−B)cos θ  (2)

Where, A: the thickness of the damper member 12, B: the thickness of theelastic member 11.

When a condition is W<Z, the case 4 (not illustrated in FIG. 7) and theelastic member 11 is not in contact with each other. Therefore, thecondition becomes X sin θ<(A−B)cos θ, which can be rewritten as thefollowing expression (3).X<(A−B)cos θ/sin θ  (3)

Therefore, when the damper member 12 is disposed at a positionrepresented by X that satisfies the condition of the expression (3), thecase 4 and the elastic member 11 are not in contact with each other. Forexample, in a case of A: 0.25 mm, B: 0.12 mm, θ: 3°, X<2.4 mm.

<4. About Configuration Regarding Back Yoke>

Next, the configuration regarding the back yoke 7 will be described withreference to FIGS. 8 and 9. FIG. 8 is an overall perspective view of aback yoke 7. FIG. 9 is a partially enlarged perspective viewillustrating a state in which the case 4 is removed from the vibrationmotor 15. FIG. 9 illustrates a configuration of the periphery of thefirst substrate portion 21 of the substrate 2.

As illustrated in FIG. 8, the back yoke 7 has a rectangular top surfaceportion 71, two long side protrusion portions 72, and two short sideprotrusion portions 73 and these portions are formed as one piece. Thelong side protrusion portion 72 protrudes downward from each long sideportion 711 of the top surface portion 71. The short side protrusionportion 73 protrudes downward from each short side portion 712 of thetop surface portion 71. The top surface portion 71 has notch portions C1at four corners. Therefore, when the back yoke 7 is formed from a platematerial, when the long side protrusion portion 72 and the short sideprotrusion portion 73 are formed by being bent from the top surfaceportion 71, the long side protrusion portion 72 and the short sideprotrusion portion 73 do not come in contact with each other.

In addition, as illustrated in FIG. 9, an end portion of the lead wire31 taken out from the short side of the coil 3 in the first direction isconnected and fixed to the each second terminal portion 23A provided atthe connection portion 23 of the substrate 2 by a solder fixing portionR. The end portion of the lead wire 31 to be fixed is disposed below theshort side protrusion portion 73 of the back yoke 7. In other words, aportion of the lead wire 31 is disposed below the short side protrusionportion 73.

Here, the short side protrusion portion 73 has a protrusion amountsmaller than that of the long side protrusion portion 72. Therefore,even if the lead wire 31 is taken out from the short side of the coil 3,disconnection of the lead wire 31 can be suppressed and space saving isachieved.

In addition, the solder fixing portion R is disposed below the shortside protrusion portion 73. In other words, below the short sideprotrusion portion 73, a solder fixing portion R to which a portion ofthe lead wire 31 is fixed to the substrate 2 is disposed. This makes itpossible to prevent the back yoke 7 from coming into contact with thesolder fixing portion R and from destroying the solder fixing portion Rduring normal vibration of the vibrating body 10.

In addition, in order to suppress disconnection of the lead wire 31, anadhesive Q is provided so as to cover the lead wire 31 and the solderfixing portion R. The adhesive Q contacts the short side of the coil 3.The adhesive Q is disposed below the short side protrusion portion 73.Therefore, when the vibrating body 10 vibrates normally, the back yoke 7comes into contact with the adhesive Q, and thus it is possible tosuppress the generation of noise.

In addition, a penetration hole 71A penetrating through the top surfaceportion 71 of the back yoke 7 in the vertical direction is providedtherein. In other words, a penetration hole 71A is provided on thesurface of the back yoke 7 to which the magnet 6 is fixed.

Accordingly, for example, in a state where the magnet 6 is fixed to thetop surface portion 71 by a magnetic force, when where the magnet 6 isfixed to the top surface portion 71 by pouring the adhesive into thepenetration hole 71A, the protrusion of the adhesive to the outside ofthe magnet 6 can be suppressed.

In addition, for example, in a state where the adhesive is applied inadvance to the peripheral region of the penetration hole 71A or asurface of the magnet 6 corresponding to the peripheral region thereof,even in a case of method in which the magnet 6 and the top surfaceportion 71 are brought into contact with each other and then the magnet6 is fixed to the top surface portion 71, since a portion of theadhesive flows into an inside portion of the penetration hole 71A, theprotrusion of the adhesive to the outside of the magnet 6 can besuppressed. In other words, the adhesive can escape to the penetrationhole 71A.

In addition, for example, like the magnet 6, in a state where theadhesive is applied in advance to the peripheral region of thepenetration hole 71A or the surface of the weight 8 corresponding to theperipheral region of the penetration hole 71A, even in a case of methodin which the weight 8 and the top surface portion 71 come into contactwith each other and the weight 8 is fixed to the top surface portion 71,a portion of the adhesive can escape into the inside portion of thepenetration hole 71A and the protrusion of the adhesive to the outsideof the weight 8 can be suppressed.

<5. About Constitution of Substrate>

Next, a more specific configuration of the substrate 2 will be describedwith reference to FIG. 10 and FIG. 11. FIG. 10 is a perspective viewillustrating a configuration in which a substrate 2 and a coil 3 aredisposed on a base plate 1 of the vibration motor 15. FIG. 11 is aperspective view illustrating a configuration in which a substrate 2 isdisposed on a base plate 1 of the vibration motor 15. In other words,FIG. 11 illustrates the state in which the coil 3 is omitted from astate of FIG. 10.

The coil 3 has an internal space 32 on the inner peripheral sidethereof. A penetration region 221 penetrating in the vertical directionis formed on the second substrate portion 22 of the substrate 2. In thetop view, an edge portion of the internal space 32 overlaps a straightline portion at the edge portion of the penetration region 221. In otherwords, the substrate 2 has the penetration region 221 penetrating atleast on the inner peripheral side of the coil 3 in the verticaldirection. Accordingly, a stroke of the vibrating body 10 can beincreased. The edge portion of the penetration region 221 may bedisposed on the inner peripheral side or the outer peripheral side fromthe edge portion of the internal space 32.

In addition, the edge portion of the penetration region 221 includes along side edge portion 221A facing in the first direction and a shortside edge portion 221B facing in the second direction. Three notchportions C2 recessed toward the outer peripheral side thereof are formedin each long side edge portion 221A. Further, a notch portion C3recessed toward the outer peripheral side thereof is formed on fourcorners of the edge portion of the penetration region 221, that is, on aplace where the long side edge portion 221A and the short side edgeportion 221B are close to each other. In other words, a plurality ofnotch portions are provided at the edge portion of the penetrationregion 221.

When the coil 3 is fixed to the base plate 1, an adhesive is applied toeach of the notch portions C2 and C3. While the second substrate portion22 is interposed between the coil 3 and the base plate 1, the coil 3 canbe fixed to the base plate 1 by the coil 3 being pressed against thesecond substrate portion 22 from above each of the notch portions C2 andC3. Therefore, peeling of the substrate 2 from the base plate 1 can besuppressed.

In addition, in the second substrate portion 22, a closed path pattern24 is provided on the periphery of the penetration region 221. Theclosed path pattern 24 is a closed wiring pattern (for example, a copperfoil pattern) and no current flows. In addition, the closed path pattern24 is formed on the inside portion of the substrate 2 in FIG. 11, butmay be exposed on the upper surface of the substrate 2. In addition, theclosed path pattern 24 in FIG. 11 has a shape in which both end portionsthereof are not connected to each other, but may be a pattern in whichboth end portions are connected to each other, that is, may be anannular pattern. Alternatively, the closed path pattern 24 may be astraight line pattern which is divided corresponding to each side of theedge portion of the penetration region 221.

This makes it possible to reinforce the strength of the second substrateportion 22 of which strength is weakened by providing the penetrationregion 221, by the closed path pattern 24.

<6. About Configuration of Base Plate>

Next, a more specific configuration of the base plate 1 will bedescribed. As illustrated in FIG. 11, in the region in the penetrationregion 221 of the base plate 1, two hole portions 1A and 1B penetratingvertically with different shapes from each other are provided. The holeportions 1A and 1B are arranged in the first direction.

The hole portions 1A and 1B are used when the coil 3 is fixed to thesubstrate 2. As illustrated in FIG. 12, when the coil 3 is fixed to thesubstrate 2, a jig (bobbin) 100 is used. The jig 100 has a base portion101 and bosses 102 and 103 protruding downward from the base portion101. The boss 102 has a cross-sectional shape corresponding to the holeportion 1A and the boss 103 has a cross-sectional shape corresponding tothe hole portion 1B.

The boss 102 of the jig 100 in a state where a coil 3 is wound aroundthe base portion 101 is penetrated through the hole portion 1A, the boss103 is penetrated through the hole portion 1B, and thus the coil 3 isdisposed on the substrate 2. At this time, as described above, since theadhesive is applied to each of the notch portions C2 and C3 of thesubstrate 2, the coil 3 is fixed to the base plate 1. Thereafter, thejig 100 is removed from the coil 3.

Since the hole portions 1A and 1B have shapes different from each other,it is possible to easily align the jigs 100 in the fixing operation ofthe coil 3.

In addition, as illustrated in FIG. 11 and the like, a recessed notchportion 1C is provided in each side portion of the base plate 1 facingin the second direction. In the example of FIG. 11, three recessed notchportions 1C are provided side by side in the first direction for eachside portion.

On the other hand, as illustrated in FIG. 1 and FIG. 2, the case 4 hasside surface portions 42 that face in the second direction. Each of theside surface portions 42 has a projection portion 4A protrudingdownward. Three projection portions 4A are provided side by side in thefirst direction for each side surface portion 42.

Each projection portion 4A is fitted into the corresponding recessednotch portion 1C. Accordingly, when the case 4 is fixed to the baseplate 1, the case 4 is likely to be aligned.

<7. Other>

Hereinafter, although embodiments of the invention are described, withinthe scope of the spirit of the present invention, various modificationsof the embodiment are possible.

For example, the elastic member is not limited to the elastic member 11described above, and may be a plurality of leaf springs disposed side byside on the weight 8 or a wound spring.

The invention can be used for a vibration motor provided in, forexample, a smartphone, a wearable device, or the like.

Features of the above-described preferred embodiments and themodifications thereof may be combined appropriately as long as noconflict arises.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

What is claimed is:
 1. A vibration motor comprising: a stationaryportion which has a base plate, a substrate, a coil, and a case; avibrating body which has a magnet, a back yoke, and a weight and issupported by the stationary portion so as to be capable of vibrating ina vertical direction; and an elastic member; wherein the substrate isdisposed on the base plate, the coil is disposed on the substrate, themagnet is disposed so as to be accommodated on an inner peripheral sideof the coil having an annular shape by vibration, the back yoke isdisposed on the magnet, the weight is disposed on the back yoke, thecase accommodates the coil, the magnet, the back yoke, and the weight,the elastic member is disposed between the case and the weight, the baseplate, the case, the magnet, the back yoke, and the weight each have arectangular shape including long sides that extend in a first directionorthogonal to the vertical direction and short sides that extend in asecond direction orthogonal to the vertical direction and the firstdirection in a top view, and the elastic member includes: a firstextension portion which extends in the first direction, a secondextension portion which extends in the first direction, a firstconnection portion which directly physically connects one end portion ofthe first extension portion and one end portion of the second extensionportion to each other, a second connection portion which directlyphysically connects another end portion of the first extension portionand another end portion of the second extension portion to each other, athird extension portion which extends in the first direction and facesthe first extension portion in the second direction, a fourth extensionportion which extends in the first direction, a third connection portionwhich directly physically connects one end portion of the thirdextension portion and one end portion of the fourth extension portion toeach other, a fourth connection portion which directly physicallyconnects another end portion of the third extension portion and anotherend portion of the fourth extension portion to each other, and a fifthconnection portion which directly physically connects a center portionof the first extension portion and a center portion of the thirdextension portion to each other in the second direction.
 2. Thevibration motor according to claim 1, wherein the first extensionportion is inclined upward from the center portion toward both the endportions thereof, the second extension portion is inclined upward fromboth the end portions toward the center portion thereof, the thirdextension portion is inclined upward from the center portion to both theend portions thereof, and the fourth extension portion is inclinedupward from both the end portions toward the center portion thereof. 3.The vibration motor according to claim 1, wherein the first extensionportion is inclined downward from the center portion toward both the endportions thereof, the second extension portion is inclined downward fromboth the end portions toward the center portion thereof, the thirdextension portion is inclined downward from the center portion towardboth the end portions thereof, and the fourth extension portion isinclined downward from both the end portions toward the center portionthereof.
 4. The vibration motor according to claim 1, wherein widths ofthe first to fourth connection portions are larger than widths of thefirst to fourth extension portions.
 5. The vibration motor according toclaim 1, wherein at least one damper member is disposed in a regionsurrounded by the first extension portion, the second extension portion,the first connection portion, and the second connection portion, andwherein at least one damper member is disposed in a region surrounded bythe third extension portion, the fourth extension portion, the thirdconnection portion, and the fourth connection portion.
 6. The vibrationmotor according to claim 1, wherein at least one damper member isdisposed in a region interposed between the first extension portion andthe third extension portion.
 7. The vibration motor according to claim1, wherein at least one damper member is disposed in an area occupied bythe elastic member in a top view.
 8. The vibration motor according toclaim 1, wherein the back yoke includes a rectangular top surfaceportion, a long side protrusion portion which protrudes downward fromthe long side portion of the top surface portion, and a short sideprotrusion portion which protrudes downward from a short side portion ofthe top surface portion, a protrusion amount of the short sideprotrusion portion is smaller than that of the long side protrusionportion, and a portion of a lead wire extending from a short side of thecoil is disposed below the short side protrusion portion.
 9. Thevibration motor according to claim 8, wherein an adhesive covering aportion of the lead wire is disposed below the short side protrusionportion.
 10. The vibration motor according to claim 8, wherein a solderfixing portion which causes a portion of the lead wire to be fixed tothe substrate is disposed below the short side protrusion portion. 11.The vibration motor according to claim 1, wherein a penetration holewhich penetrates in a vertical direction is provided in a surface of theback yoke to which the magnet is fixed.
 12. The vibration motoraccording to claim 1, wherein the substrate includes a penetrationregion which penetrates vertically therethrough at least on an innerperipheral side of the coil.
 13. The vibration motor according to claim12, wherein a plurality of notch portions are provided at an edgeportion of the penetration region.
 14. The vibration motor according toclaim 12, wherein a closed path pattern is provided along the peripheryof the penetration region.
 15. The vibration motor according to claim12, wherein two hole portions which have different shapes from eachother and penetrate in the vertical direction are provided in a regioninside the penetration region of the base plate.
 16. The vibration motoraccording to claim 1, wherein a recessed notch portion is provided ineach of side portions of the base plate that face each other in thesecond direction, the case includes side surface portions that opposeeach other in the second direction, each of the side surface portionsincludes a projection portion which protrudes downward, and theprojection portions are fitted into the recessed notch portions.
 17. Thevibration motor according to claim 2, wherein the fourth extensionportion includes a welded portion at an uppermost portion of itsinclination.